Claude Fable 5.1 vs Claude Opus 5
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
| Dimension | Claude Fable 5.1 | Claude Opus 5 | Advantage |
|---|---|---|---|
| Capability | 73% | 47% | +27% (Claude Fable 5.1 leads) |
| Median task time | 1m 46s | 3m 8s | 1m 22s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.026 / task | $0.008 / task | $0.017 / task lower (Claude Opus 5 leads) |
Claude Fable 5.1: 28.0% of Claude Max 20x (28.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Claude Opus 5: 9.0% of Claude Max 20x (9.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
Work per window: Claude Fable 5.1 522 vs Claude Opus 5 1623 suite runs per month (Claude Opus 5 leads); per plan-dollar: 2.61 vs 8.12 (Claude Opus 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5.1 | Claude Opus 5 | Advantage |
|---|---|---|---|
| Capability | 74% | 70% | +4% (Claude Fable 5.1 leads) |
| Median task time | 6m 51s | 5m 15s | 1m 36s faster (Claude Opus 5 leads) |
| Approx. task cost | $0.051 / task | $0.014 / task | $0.038 / task lower (Claude Opus 5 leads) |
Claude Fable 5.1: 15.0% of Claude Max 20x (15.0% / 5h, 2.0% / 1w) per run. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Claude Opus 5: 4.0% of Claude Max 20x (4.0% / 5h) per run. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
Work per window: Claude Fable 5.1 974 vs Claude Opus 5 3653 suite runs per month (Claude Opus 5 leads); per plan-dollar: 4.87 vs 18.26 (Claude Opus 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
| Dimension | Claude Fable 5.1 | Claude Opus 5 | Advantage |
|---|---|---|---|
| Capability | 85% | 69% | +15% (Claude Fable 5.1 leads) |
| Median task time | 3m 48s | 5m 15s | 1m 27s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.025 / task | $0.011 / task | $0.014 / task lower (Claude Opus 5 leads) |
Claude Fable 5.1: 1.8% of Claude Max 20x (1.8% / 5h, 0.2% / 1w) per good solve. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Claude Opus 5: 0.8% of Claude Max 20x (0.8% / 5h) per good solve. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Each figure is a share of that agent's own plan, so there is no delta to draw.
Work per window: Claude Fable 5.1 8117 vs Claude Opus 5 18263 good solves per month (Claude Opus 5 leads); per plan-dollar: 40.58 vs 91.31 (Claude Opus 5 leads). Work figures compare outputs, so unlike quota shares they are comparable across plans.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, Claude Fable 5.1 or Claude Opus 5?
Both clear tier 4 of 5, but Claude Fable 5.1 scores higher on capability: 73% versus 47% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-01.
Which gives more work per dollar, Claude Fable 5.1 or Claude Opus 5?
Claude Opus 5 delivers more benchmark work per subscription dollar: 8.12 suite runs per plan-dollar versus 2.61 for Claude Fable 5.1 (at $200/month priced 2026-08-05, and $200/month priced 2026-08-05). Work figures compare outputs, so unlike raw quota shares they are comparable across plans.
How much do Claude Fable 5.1 and Claude Opus 5 cost?
Claude Fable 5.1 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). Claude Opus 5 runs on Claude Max 20x at $200/month (public price as of 2026-08-05).